replace time.time with custom datetime string of deterministic length (14) that ignores milliseconds
Remove untrusted comments from Signature class completely
Trusted comment of Signature class replaced by "Subject"
Subject is now first field of Signature
Subject is now of fixed format {blake2b(input):{deterministic_datetime}}, this is designed for the use case of addressing a signed package to a particular node. for example: sk.sign(subject="recipient") will create the subject "hashed_recipient:deterministic_datetime"
Remove prefixes from comment and signature
restructure signature drop and load to work with our new signature structure